Blood test study points to earlier clarity on canine splenic masses

Veterinarians may be getting closer to a blood test that helps answer one of small-animal practice’s hardest emergency questions: is this splenic mass benign, or is it hemangiosarcoma? A 2026 American Journal of Veterinary Research study, discussed this week on AVMA’s Veterinary Vertex podcast, found that a four-microRNA serum panel could discriminate dogs with splenic hemangiosarcoma from dogs with noncancerous splenic masses with 80% sensitivity and 90% specificity. (researchgate.net)

That matters because the current diagnostic pathway is still full of uncertainty. The American College of Veterinary Surgeons notes that final diagnosis for splenic masses generally depends on microscopic examination after splenectomy, even though benign lesions such as hematoma and nodular hyperplasia can look clinically similar to hemangiosarcoma. ACVS also notes that while “up to two-thirds” of splenic masses are malignant and many of those are hemangiosarcoma, those rules are broad guides, not case-specific answers. (acvs.org)

The new study focused on serum biomarkers that could be measured before surgery. According to the study summary, investigators evaluated serum from 10 dogs with splenic hemangiosarcoma and 20 dogs with noncancerous splenic masses, then used quantitative reverse transcription PCR and multivariable logistic regression to identify the best-performing combination. The resulting four-marker panel — miR-126-5p, miR-150-5p, miR-452-5p, and miR-543 — produced an AUC of 0.930, with 80% sensitivity and 90% specificity for distinguishing hemangiosarcoma from noncancerous splenic masses. The authors said the clinical value is in giving veterinarians and pet parents better information before surgery, including whether to prepare for adjuvant therapy if hemangiosarcoma is likely. (researchgate.net)

This paper builds on a longer line of work in canine splenic mass diagnostics. Earlier research identified differential microRNA expression in splenic hemangiosarcoma tissue and pointed to the possibility of a future blood-based test. More recently, a 2025/2026 pathology study reported that serum and tissue microRNAs could differentiate splenic hemangiosarcoma from other splenic masses, and PubMed’s summary of that work described a five-microRNA serum model that classified dogs with hemangiosarcoma versus normal dogs and dogs with benign splenic masses with very high accuracy in that dataset. Taken together, the field appears to be moving from exploratory biomarker discovery toward more clinically targeted panels. (pmc.ncbi.nlm.nih.gov)

The Veterinary Vertex discussion adds useful real-world framing. Dr. Janet Grimes describes a multi-marker microRNA panel as a send-out style adjunct that could eventually evolve into a cage-side diagnostic, while also emphasizing practical barriers, including distinguishing hemangiosarcoma from other splenic malignancies and avoiding misleading results in medically unstable dogs. The same podcast positions the assay alongside physical exam, imaging, and standard lab work rather than as a standalone answer. (poddtoppen.se)

Why it matters: For clinicians, this is less about replacing splenectomy than about improving decision support before the scalpel. Splenic masses often present in urgent settings, sometimes with hemoabdomen, and pet parents may be asked to make rapid choices with incomplete information. A test with good specificity could be especially useful in counseling families about whether surgery is more likely to reveal a benign process versus hemangiosarcoma, while a test with imperfect sensitivity still means negative results would need careful interpretation. In practice, that could make these assays most valuable as part of a broader triage and counseling framework, especially in referral, emergency, and oncology settings. (researchgate.net)

There are still important caveats. The reported study sample was small, and the performance metrics come from a controlled research cohort rather than broad, real-world deployment. It’s also not yet clear from the available materials how the panel will perform across breed groups, concurrent illness, hemoabdomen severity, or other splenic malignancies that can complicate differential diagnosis. Those questions will matter if the field wants to move from promising proof of concept to a widely adopted clinical tool. (researchgate.net)

What to watch: The next milestones are likely to be prospective validation in larger case sets, head-to-head assessment against existing preoperative workflows, and any commercial or academic effort to turn microRNA testing into a standardized send-out or point-of-care assay for dogs with splenic masses. (poddtoppen.se)